diff --git a/cmake/CMakeLists.txt b/cmake/CMakeLists.txt
index 47a53706f9..3f3acbbf4c 100644
--- a/cmake/CMakeLists.txt
+++ b/cmake/CMakeLists.txt
@@ -18,7 +18,7 @@
 ################################################################################
 
 cmake_minimum_required(VERSION 3.1.3)
-set(CMAKE_CXX_STANDARD 11)
+set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)  # not necessary, but encouraged
 
 project (IfcOpenShell)
diff --git a/nix/build-all.py b/nix/build-all.py
index 5fd1b6922c..433787130f 100644
--- a/nix/build-all.py
+++ b/nix/build-all.py
@@ -97,7 +97,7 @@ SWIG_VERSION="3.0.12"
 OPENCOLLADA_VERSION="v1.6.68"
 GMP_VERSION="6.1.2"
 MPFR_VERSION="3.1.5"
-CGAL_VERSION="4.14.3"
+CGAL_VERSION="5.2"
 
 # binaries
 cp="cp"
@@ -253,7 +253,7 @@ print("Building:", *sorted(targets, key=lambda t: len(list(v(t)))))
 
 # Check that required tools are in PATH
 
-for cmd in [git, bunzip2, tar, cc, cplusplus, autoconf, automake, yacc, make, "patch", "m4"]:
+for cmd in [git, bunzip2, tar, cc, cplusplus, autoconf, automake, yacc, make, "patch", "m4", "cmake"]:
     if which(cmd) is None:
         raise ValueError("Required tool '%s' not installed or not added to PATH" % (cmd,))
 
@@ -320,7 +320,8 @@ def run_cmake(arg1, cmake_args, cmake_dir=None, cwd=None):
         P=".."
     else:
         P=cmake_dir
-    cmake_path= os.path.join(DEPS_DIR, "install", "cmake-%s" % (CMAKE_VERSION,), "bin", "cmake")
+    # @todo this is already in v0.6
+    cmake_path = "cmake"
     run([cmake_path, P]+cmake_args+["-DCMAKE_BUILD_TYPE=%s" % (BUILD_CFG,)], cwd=cwd)
 
 def git_clone_or_pull_repository(clone_url, target_dir, revision=None):
@@ -481,27 +482,6 @@ os.environ["CXXFLAGS"] = CXXFLAGS
 os.environ["CFLAGS"] = CFLAGS
 os.environ["LDFLAGS"] = LDFLAGS
 
-# Some dependencies need a more recent CMake version than most distros provide
-build_dependency(name="cmake-%s" % (CMAKE_VERSION,), mode="autoconf", build_tool_args=[], download_url="https://cmake.org/files/v%s" % (CMAKE_VERSION_2,), download_name="cmake-%s.tar.gz" % (CMAKE_VERSION,))
-
-# Extract compiler flags from CMake to harmonize settings with other autoconf dependencies
-CMAKE_FLAG_EXTRACT_DIR="ifcopenshell_cmake_test_%s" % (time.time(),)
-# was sp.check_output([bash, "-c", "cat /dev/urandom | env LC_CTYPE=C tr -dc 'a-zA-Z0-9' | head -c 32"]), in bash script, unclear what the exact required format is and whether it's needed
-if os.path.exists(CMAKE_FLAG_EXTRACT_DIR):
-    shutil.rmtree(CMAKE_FLAG_EXTRACT_DIR)
-os.makedirs(CMAKE_FLAG_EXTRACT_DIR)
-BUILD_CFG_UPPER=BUILD_CFG.upper()
-for FL in ["C", "CXX"]:
-    run([bash, "-c", """echo "
-    message(\"\${CMAKE_%s_FLAGS_%s}\")
-    " > CMakeLists.txt""" % (FL, BUILD_CFG_UPPER)], cwd=CMAKE_FLAG_EXTRACT_DIR)
-    FL="%sFLAGS" % (FL,)
-    FLM="%sFLAGS_MINIMAL" % (FL,)
-# @TODO: bash code unclear
-#    exec("%sFLAGS=%s" % (FL, sp.check_output([os.path.join(DEPS_DIR, "install", "cmake-%s" % (CMAKE_VERSION,), "bin", "cmake"), "."
-#    declare ${FL}FLAGS_MINIMAL="`$DEPS_DIR/install/cmake-$CMAKE_VERSION/bin/cmake . 2>&1 >/dev/null` ${!FLM}"
-shutil.rmtree(CMAKE_FLAG_EXTRACT_DIR)
-
 if "json" in targets:
     json_url = "https://github.com/nlohmann/json/releases/download/{JSON_VERSION}/json.hpp".format(**locals())
     json_install_path = "{DEPS_DIR}/install/json/nlohmann/json.hpp".format(**locals())
@@ -676,7 +656,8 @@ if "cgal" in targets:
     build_dependency(
         name="cgal-{CGAL_VERSION}".format(**locals()),
         mode="cmake",
-        patch="./patches/cgal/cgal_4768.patch",
+        # applied upstream
+        # patch="./patches/cgal/cgal_4768.patch",
         build_tool_args=[
             "-DGMP_LIBRARIES=%s/install/gmp-%s/lib/libgmp.a" % (DEPS_DIR, GMP_VERSION),
             "-DGMP_INCLUDE_DIR=%s/install/gmp-%s/include" % (DEPS_DIR, GMP_VERSION),
@@ -684,11 +665,13 @@ if "cgal" in targets:
             "-DMPFR_INCLUDE_DIR=%s/install/mpfr-%s/include" % (DEPS_DIR, MPFR_VERSION),
             "-DBoost_INCLUDE_DIR=%s/install/boost-%s" % (DEPS_DIR, BOOST_VERSION),
             "-DCMAKE_INSTALL_PREFIX=%s/install/cgal-%s/" % (DEPS_DIR, CGAL_VERSION),
+            # for now as the IfOpSh CMakeL expects libraries, we can probably safely turn this off though
+            "-DCGAL_HEADER_ONLY=OFF",            
             "-DBUILD_SHARED_LIBS=Off"],
         download_url="https://github.com/CGAL/cgal.git",
         download_name="cgal",
         download_tool=download_tool_git,
-        revision="releases/CGAL-{CGAL_VERSION}".format(**locals())
+        revision="v{CGAL_VERSION}".format(**locals())
     )
     BUILD_CFG = OLD_BUILD_CFG